Recently, battery devices are used in various products. In cases where the power to be used is large, the capacity of batteries also needs to be increased. With such increased capacity of battery devices, it is desired to ensure safety and reliability.
As a battery device increases in capacity, the number of its internal battery cells also increases, and the price also increases. For this reason, there is a fear that the user may disassemble the battery device and replace the internal battery cells with cheaper ones in an unauthorized manner.
The present applicant has previously proposed providing an IC chip inside a battery device, and making the IC chip store an identification number (for example, PTL 1). Consequently, by reading the identification number from the battery device, and performing an authentication process on the basis of the identification number that has been read, it is possible to discover and eliminate an invalid battery device.